Exposure and Implant Options in Revision Total Knee Arthroplasty

50 Exposure and Implant Options in Revision Total Knee Arthroplasty

Felipe Moreira MD, Maria Jurado MD, and Marcelo Casaccia MD

Hospital Vall d’Hebron, Barcelona, Spain

Clinical scenario

  • A 72‐year‐old, active woman with a right total knee arthroplasty (TKA) performed 12 years ago complains of pain and locking in her right knee.
  • She is having difficulty ascending and descending stairs for a year now, and requires a walking aid, even when walking a few hundred meters.
  • On examination, the right knee is unstable in varus‐valgus, and on X‐ray, there is a valgus collapse of the tibia indicating the possibility of loosening.
  • After ruling out infection a revision TKA is indicated.

Top three questions

  1. In patients undergoing revision TKA, does one surgical approach, compared to others, result in optimal outcomes?
  2. In patients undergoing revision TKA, does a tibial tubercle osteotomy (TTO), compared to quadriceps snip (QS), result in improved functional outcomes and fewer complications?
  3. In patients undergoing revision TKA and requiring augmentation due to bone defects, do metaphyseal cones, compared to sleeves, result in better outcomes ?

Question 1: In patients undergoing revision TKA, does one surgical approach, compared to others, result in optimal outcomes?


Controversy exists when regarding the best surgical approach for revision total knee arthroplasty (rTKA). Such an approach should ideally have delicate management of the soft tissue envelope and reduce the risk of extensor mechanism complications.

Clinical comment

Obtaining an adequate surgical exposure is among the first and most important steps in performing an rTKA. Objectives include protecting the extensor mechanism, safely removing the implanted components, and obtaining adequate visualization to prepare the bony surfaces for the revision components.1 Challenges to these goals include prior skin incisions, dense scarring, and the presence of patella baja.

Available literature and quality of the evidence

  • Level I: 1 randomized controlled study.2
  • Level II: 1 retrospective cohort study.3
  • Level IV: 5 retrospective case series.48
  • Level V: 1 cadaveric study.9


During the exposure there are three important decisions to be made while dissecting toward the prosthetic components.10

Skin incision

Blood supply to the anterior aspect of the knee is predominantly derived from the medial side, and it travels from deep to superficial layers. Hence, if there are many previous incisions, the most lateral one should be utilized, and full thickness skin flaps should be developed, as well as excision of the scar tissue. Transverse scars should be transected at a perpendicular angle to prevent skin necrosis. Patients with multiple scars and densely adherent skin may require a preoperative consultation with a plastic surgeon.

Capsular approach

The workhorse approach to the knee is the medial parapatellar capsular incision. When performed associated with an accurate anterior and posterior intra‐articular synovectomy, it provides an adequate exposure for most revision TKAs.8

Using extensor mechanism tenolysis and scar removal technique, eversion of the patella and removal of components is readily accomplished for the vast majority of patients.7 After that, the patella inversion method affords adequate exposure in most patients without violating the extensor mechanism.4

Mobilization of the extensor mechanism

If at this point in the procedure the exposure is inadequate, an extensive exposure of the knee is required to increase patellar excursion while maintaining the function of the extensor mechanism. It is a critical step, and it should aim to minimize the risk of patellar tendon disruption, quadriceps tendon rupture, patellar crepitus, and soft tissue impingement, periprosthetic patella fracture, patellofemoral instability, and osteonecrosis of the patella. The decision to extend the incision proximally, distally, or in combination should be determined on an individual basis.

Proximally, relaxation of the quadriceps tendon can be achieved by a QS.5,11 Technically easier, it does not require an alteration in the postoperative physical therapy and it shows similar clinical outcomes as those achieved using an isolated medial parapatellar approach (MPA). However, some studies have demonstrated an increased risk of implant malalignment in primary TKA.12 An extensive MPA increases the mobility and excursion of the patella to the same extent as the QS technique, and it is theoretically safer in terms of preservation of quadriceps tendon integrity.9

The V‐Y modified quadricepsplasty (QP) is rarely indicated given the risk of postoperative extensor lag. Notwithstanding the possible extension lag, Zhamilov et al. conclude that QP is as effective as QS when extensile exposure is required and may be used safely, although weightbearing is delayed postoperatively.3 In general, however, it is considered only when a TTO is contraindicated and there is severe stiffness. Distally, the exposure can be improved by a TTO, which gives the greatest degree of exposure and it is useful in patients with stiff or ankylosed knees, in cases of patella baja or when a well‐fixed cemented tibial stem should be removed. TTO should be considered the gold standard in extensile exposure, but it is a technically demanding procedure and also associated with some complications if it is done without a strict technique.

Resolution of clinical scenario

  • The appropriate surgical exposure for any revision procedure should be determined by careful preoperative planning based on the assessment of the previous exposures used, of the type of implant to be removed, and the extent of bone deficiencies to be reconstructed.
  • A medial capsular approach with a thorough intra‐articular release and extensor mechanism tenolysis provides adequate exposure for the majority of revision cases. If additional exposure is needed, a QS through tendon or an extensive MPA is often helpful, and does not alter the postoperative rehabilitation protocol.
  • Surgeons performing difficult rTKA cases should be familiar with a range of approaches and must be aware of proximal and distal extension procedures.
  • Further studies, preferably in a prospective randomized fashion, are required to define the differences between the more extensile approaches.

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Nov 28, 2021 | Posted by in ORTHOPEDIC | Comments Off on Exposure and Implant Options in Revision Total Knee Arthroplasty

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